U.S. patent number 5,831,962 [Application Number 08/779,148] was granted by the patent office on 1998-11-03 for optical pickup carrying system.
This patent grant is currently assigned to Mitsubishi Denki Kabushiki Kaisha. Invention is credited to Shigehiro Itou, Naohiko Obata, Tsunemi Sakai.
United States Patent |
5,831,962 |
Sakai , et al. |
November 3, 1998 |
Optical pickup carrying system
Abstract
An optical pickup carrying system includes a base on which a
turn table can be disposed rotatably for placing a disk thereon, an
optical pickup movably disposed in the base for reading a signal
recorded on the disk, a guide rail disposed in the base and
provided with sliding surfaces on which a level positioning member
secured to the optical pickup and a plate spring can slide,
respectively, for guiding and supporting the optical pickup in
cooperation with the level positioning member and plate spring when
the optical pickup moves, and a groove formed in the sliding
surface for storing grease.
Inventors: |
Sakai; Tsunemi (Tokyo,
JP), Itou; Shigehiro (Tokyo, JP), Obata;
Naohiko (Tokyo, JP) |
Assignee: |
Mitsubishi Denki Kabushiki
Kaisha (Tokyo, JP)
|
Family
ID: |
16949449 |
Appl.
No.: |
08/779,148 |
Filed: |
January 3, 1997 |
Foreign Application Priority Data
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Sep 3, 1996 [JP] |
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8-233077 |
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Current U.S.
Class: |
720/672; 720/663;
G9B/7.056 |
Current CPC
Class: |
G11B
7/08582 (20130101) |
Current International
Class: |
G11B
7/085 (20060101); G11B 021/16 (); G11B
021/02 () |
Field of
Search: |
;369/215,218,219,220,223,224,244,249 ;384/13 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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61-168436 |
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Jul 1986 |
|
JP |
|
62-78782 |
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Apr 1987 |
|
JP |
|
62-250564 |
|
Oct 1987 |
|
JP |
|
63-029381 |
|
Feb 1988 |
|
JP |
|
5-332358 |
|
Dec 1993 |
|
JP |
|
6-302129 |
|
Oct 1994 |
|
JP |
|
7-287138 |
|
Oct 1995 |
|
JP |
|
Primary Examiner: Levy; Stuart S.
Assistant Examiner: Klimowicz; William J.
Claims
What is claimed is:
1. An optical pickup carrying system comprising:
a base having a turn table disposed thereon for rotating a
recording medium;
an optical pickup, movably disposed on said base, for reading
information from the recording medium;
a support means coupled to said optical pickup for supporting said
optical pickup;
a guide rail disposed on said base, said guide rail having at least
one sliding surface on which said support means can slide so as to
move said optical pickup along said guide rail; and
lubricating agent storing means formed as at least one depression
in at least one sliding surface of said guide rail for retaining
lubricating agent previously provided on the sliding surface,
wherein said guide rail has an upper sliding surface and a lower
sliding surface on which said support means can slide, and said
lubricating agent storing means retains lubricating agent on at
least one of the two sliding surfaces,
wherein said lubricating agent storing means includes at least one
row of plural cavities formed on at least one of the upper sliding
surface and lower sliding surface and running in parallel with a
direction of optical pickup movement.
2. The optical pickup carrying system according to claim 1, wherein
said lubricating agent storing means includes at least one groove
formed on at least one of the upper sliding surface and the lower
sliding surface of said guide rail and running in parallel with a
direction of optical pickup movement.
3. The optical pickup carrying system according to 1, wherein said
lubricating agent storing means includes at least one row of
cavities formed on the upper sliding surface and running in
parallel with the direction of optical pickup movement, and at
least one row of cavities formed on the lower sliding surface and
running in parallel with the direction of optical pickup
movement.
4. The optical pickup carrying system according to claim 1, wherein
said guide rail is solid.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an optical pickup carrying system
used for a disk playback device.
2. Description of the Prior Art
Referring now to FIG. 14, there is illustrated a perspective view
of a prior art optical pickup carrying system. Furthermore, FIG. 15
shows a bottom view of the prior art optical pickup carrying
system, FIG. 16 shows a side view of the prior art optical pickup
carrying system, FIG. 17 shows a perspective view showing a main
part of a guide rail of the prior art optical pickup carrying
system, and FIG. 18 shows a cross-sectional view of a main part of
a slide portion of the prior art optical pickup carrying
system.
In these figures, reference numeral 101 denotes a base, 102 denotes
a turn table on which a disk 103 such as a CR-ROM can be placed,
and 104 denotes a spindle motor secured to the base 101, for
rotating the turn table 102.
Furthermore, reference numeral 105 denotes an optical pickup for
reading a signal recorded on the disk 103, 106 denotes a thread
motor which serves as a driving source for moving the optical
pickup 105, 107 denotes a motor base for securing the thread motor
106 to the base 101, 108 denotes a gear fixed on the rotary shaft
of the thread motor 106, and 109 denotes a gear rotatably mounted
on a shaft secured to the motor base 107.
In addition, reference numeral 110 denotes a screw shaft having a
gear 111 engaged with the gear 109 at one end thereof. The shaft
can rotate together with the gear 111. The thread of the screw
shaft 110 is engaged in a nut 112 secured to the optical pickup 105
so as to carry the optical pickup 105.
Reference numeral 113 denotes a plate spring for imposing a certain
load on the screw shaft 110 in the thrust direction so as to hold
the screw shaft 110, and 114 denotes a guide rail which is formed
integrally with the base 101 and on which a level positioning
member 115 of the optical pickup 105 and a plate spring 116, which
will be mentioned below, can slide. The guide rail 114 has upper
and lower sliding surfaces 114a and 114b. The plate spring 116 is
attached to the bottom part of the optical pickup 105 to urge the
level positioning member 115 toward the guide rail 114 so as to
support the optical pickup 105. Furthermore, reference numeral 118
denotes grease which is applied to the sliding surfaces 114a and
114b of the guide rail 114.
Next, a description will be made as to the operation of the prior
art pickup carrying system. When the optical pickup 105 reads data
from a position on a surface of the disk 103, a driving voltage
from a control circuit board not shown is applied to the thread
motor 106 to produce a driving force in the thread motor 106 which
is then transmitted to the screw shaft 110 by way of the gears 108,
109, and 111, and therefore causes the screw shaft 110 to
rotate.
When the screw shaft 110 rotates so that the optical pickup 105
having the nut 112 engaged with the screw shaft 110 is moved to the
above position in the radial direction of the disk 103, the optical
pickup 105 reads data from the above position of the disk 103.
During the movement of the optical pickup 105, the level
positioning member 115 and plate spring 116 slide on the sliding
surfaces 114a and 114b of the guide rail 114, respectively.
Accordingly, upward and downward movements of the optical pickup
105 can be restricted by the level positioning member 115 and plate
spring 116. The grease 118 in the gaps between the sliding surfaces
114a and 114b and the level positioning member 115 and plate spring
116 can serve to reduce the resistance to the sliding movements of
the level positioning member 115 and plate spring 116 against the
guide rail 114.
An extended period of use of or playing back disks many times in a
disk playback device including such the prior art optical system
having the above-mentioned structure causes a decrease in the
amount of the grease 118, which serves as a lubricating agent, due
to a spill and scattering of the grease, because the level
positioning member 115 and plate spring 116 of the optical pickup
105 slide on the guide rail 114 many times. Accordingly, the level
positioning member 115, plate spring 116, and sliding surfaces 114a
and 114b become susceptible to wear. Therefore, a problem is that
the accuracy of positioning the optical pickup 105 cannot be
maintained and hence the capability of reading data from the disk
is reduced.
SUMMARY OF THE INVENTION
The object of the present invention is to overcome the above
problem. More precisely, it is an object of the present invention
to provide an optical pickup carrying system capable of preventing
a decrease in the amount of a lubricating agent at the sliding
portion thereof and hence wear in the sliding portion, thereby
maintaining the accuracy of positioning the optical pickup.
It is another object of the present invention to provide an optical
pickup carrying system capable of decreasing the resistance to
sliding movements of the optical pickup.
It is a further object of the present invention to provide an
optical pickup carrying system capable of preventing the
lubricating agent from flowing over either of the longitudinal edge
portions of one sliding surface of the guide rail.
In accordance with the present invention, there is provided an
optical pickup carrying system including a base on which a turn
table can be disposed rotatably for placing a recording medium
shaped like a disk thereon, an optical pickup movably disposed in
the base for reproducing a signal from the disk-shaped recording
medium, a support mechanism disposed in the optical pickup for
supporting the optical pickup so that it can move on the base, a
guide rail disposed in the base and provided with at least a
sliding surface on which the support mechanism can slide when the
optical pickup moves, for guiding and supporting the optical pickup
in cooperation with the support mechanism, and a lubricating agent
storing mechanism formed in the guide rail for storing a
lubricating agent to furnish it to the sliding surface.
In accordance with a preferred embodiment of the present invention,
the guide rail has upper and lower sliding surfaces on which the
support mechanism can slide, and the lubricating storing mechanism
furnishes the lubricating agent to at least one of the two sliding
surfaces.
In accordance with another preferred embodiment of the present
invention, the lubricating agent storing mechanism is at least one
groove formed in at least one of the two sliding surfaces and
running in parallel with a direction of moving the optical
pickup.
In accordance with another preferred embodiment of the present
invention, the lubricating agent storing mechanism includes at
least one groove formed in the upper sliding surface and running in
parallel with the direction of moving the optical pickup, and at
least one groove formed in the lower sliding surface and running in
parallel with the direction of moving the optical pickup.
In accordance with another preferred embodiment of the present
invention, the lubricating agent storing mechanism includes at
least one row of cavities formed in at least one of the two sliding
surfaces and running in parallel with the direction of moving the
optical pickup.
In accordance with another preferred embodiment of the present
invention, the lubricating agent storing mechanism includes at
least one row of cavities formed in the upper sliding surface and
running in parallel with the direction of moving the optical
pickup, and at least one row of cavities formed in the lower
sliding surface and running in parallel with the direction of
moving the optical pickup.
In accordance with another preferred embodiment of the present
invention, the guide rail includes a pair of projecting portions
projected from both of longitudinal sides of the sliding surface,
and the support mechanism includes a pair of notch portions through
which the pair of projecting portions can be passed when the
optical pickup moves.
Further objects and advantages of the present invention will be
apparent from the following description of the preferred
embodiments of the invention as illustrated in the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view showing an optical pickup carrying
system according to a first embodiment of the present
invention;
FIG. 2 is a bottom view of the optical pickup carrying system of
the first embodiment shown in FIG. 1;
FIG. 3 is a side view of the optical pickup carrying system of the
first embodiment shown in FIG. 1;
FIG. 4 is a perspective view showing a main part of a guide rail of
the optical pickup carrying system of the first embodiment shown in
FIG. 1;
FIG. 5 is a cross-sectional view of a main part of a slide portion
of the optical pickup carrying system of the first embodiment shown
in FIG. 1;
FIG. 6 is a perspective view showing a main part of a guide rail of
an optical pickup carrying system of a second embodiment of the
present invention;
FIG. 7 is a cross-sectional view of a main part of a slide portion
of the optical pickup carrying system of the second embodiment
shown in FIG. 6;
FIG. 8 is a perspective view showing a main part of a guide rail of
an optical pickup carrying system of a third embodiment of the
present invention;
FIG. 9 is a cross-sectional view of a main part of a slide portion
of the optical pickup carrying system of the third embodiment shown
in FIG. 8;
FIG. 10 is a perspective view showing a main part of a guide rail
of an optical pickup carrying system of a fourth embodiment of the
present invention;
FIG. 11 is a cross-sectional view of a main part of a slide portion
of the optical pickup carrying system of the fourth embodiment
shown in FIG. 10;
FIG. 12 is a perspective view showing a main part of a guide rail
of an optical pickup carrying system of a fifth embodiment of the
present invention;
FIG. 13 is a cross-sectional view of a main part of a slide portion
of the optical pickup carrying system of the fifth embodiment shown
in FIG. 12;
FIG. 14 is perspective view showing a prior art optical pickup
carrying system;
FIG. 15 is a bottom view of the prior art optical pickup carrying
system shown in FIG. 14;
FIG. 16 is a side view of the prior art optical pickup carrying
system shown in FIG. 14;
FIG. 17 is a perspective view showing a main part of a guide rail
of the prior art optical pickup carrying system shown in FIG. 14;
and
FIG. 18 is a cross-sectional view of a main part of a slide portion
of the prior art optical pickup carrying system shown in FIG.
14.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIG. 1, there is illustrated a perspective view
showing an optical pickup carrying system according to a first
embodiment of the present invention. Furthermore, FIG. 2 shows a
bottom view of the optical pickup carrying system of this
embodiment, FIG. 3 shows a side view of the optical pickup carrying
system of this embodiment, FIG. 4 shows a perspective view showing
a main part of a guide rail of the optical pickup carrying system
of this embodiment, and FIG. 5 shows a cross-sectional view of a
main part of a slide portion of the optical pickup carrying system
of this embodiment.
In these figures, reference numeral 1 denotes a base on which a
turn table 2 for placing a disk (a recording medium shaped like a
disk) 3 such as a CD-ROM thereon is disposed rotatably, 4 denotes a
spindle motor secured to the base 1, for rotating the turn table 2,
and 5 denotes an optical pickup mounted to the base 1 such that it
can move in the directions indicated by the arrow A shown in FIG.
1, for reading a signal recorded on the disk 3.
Furthermore, reference numeral 6 denotes a thread motor which
serves as a driving source for moving the optical pickup 5, 7
denotes a motor base for securing the thread motor 6 to the base 1,
8 denotes a gear fixed on the rotary shaft of the thread motor 6,
and 9 denotes a gear rotatably mounted on a shaft secured to the
motor base 7.
In addition, reference numeral 10 denotes a screw shaft having a
gear 11 engaged with the gear 9 at one end thereof. The screw shaft
can rotate together with the gear 11. The thread of the screw shaft
10 is engaged in a nut 12 secured to the optical pickup 5.
Therefore, when the screw shaft rotates, the optical pickup 5 is
carried in either of the two directions indicated by the arrow A in
FIG. 1.
Reference numeral 13 denotes a plate spring for imposing a certain
load on the screw shaft 10 in the thrust direction so as to hold
the screw shaft 10, and 14 denotes a guide rail which is formed
integrally with the base 1 so that the guide rail is extended in
parallel with the moving directions of the optical pickup 5 and on
which a level positioning member 15 of the optical pickup 5 and a
plate spring 16, which will be mentioned below, can slide. The
upper and lower surfaces of the guide rail 14 are formed as sliding
surfaces 14a and 14b on which the level positioning member 15 of
the optical pickup 5 and the plate spring 16 can slide,
respectively. The plate spring 16 is secured to the bottom part of
the optical pickup 5 to urge the guide rail 14 towards the level
positioning member 15. That is, the plate spring 16 and level
positioning member 15 are urged towards each other and are pressed
against the sliding surfaces 14a and 14b, respectively, so as to
hold the guide rail 14 in cooperation with each other. Thus, the
level positioning member 15 and plate spring 16 support the optical
pickup 5 in cooperation with the guide rail 14 so that upward and
downward movements of the optical pickup 5 with respect to the base
1 can be restricted.
Furthermore, reference numeral 17 denotes a groove formed in the
sliding surface 14a of the guide rail and running in the direction
of moving the pickup 5. The cross-section of the groove is
generally U-shaped. The groove 17 serves to store grease 18
therein. Thereby, the storage amount of the grease 18 on the
sliding surface 14a of the guide rail 114 can be increased.
Furthermore, the groove 17 serves to prevent scattering and a spill
of the grease 18 from the sliding surface 14a. At least another
groove can be further formed in the sliding surface 14a in parallel
with the groove 17. Grease 18 is also applied to the sliding
surface 14b of the guide rail 114.
Next, a description will be made as to the operation of the optical
pickup carrying system of the present embodiment. When the optical
pickup 5 reads a signal from a position on the disk 3, a driving
voltage from a control circuit board not shown is applied to the
thread motor 6. As a result, the driving force of the thread motor
6 is transmitted to the screw shaft 10 by way of the gears 8, 9,
and 11, and then it causes the screw shaft 10 to rotate.
When the screw shaft 10 rotates so that the optical pickup 5 having
the nut 12 engaged with the screw shaft 10 is moved to the above
position in the radial direction of the disk 3, the optical pickup
5 reads a signal recorded on the position of the disk 3. During the
movement of the optical pickup 5, the level positioning member 15
and plate spring 16 slide on the sliding surfaces 14a and 14b of
the guide rail 14. Accordingly, upward and downward movements of
the optical pickup 5 can be restricted.
The grease 18 applied to the sliding surfaces 14a and 14b can serve
to reduce the resistance to the sliding movements of the level
positioning member 5 and plate spring 16 against the guide rail 14.
In this embodiment, since the grease 18 is stored in the groove 17
formed in the sliding surface 14a, scattering and a spill of the
grease 18 can be prevented as compared with the prior art pickup
carrying system mentioned above. Therefore, the longevity of the
lubricating agent is increased.
Furthermore, since the groove 17 is formed in the guide rail 14 and
is running in the direction of moving the optical pickup 5, an
adequate amount of the grease 18 can be applied to a part of the
sliding surface 14a where a lot of resistance to sliding movements
of the level positioning member 15 is generated. Thus, the effect
of lubricating can be enhanced and hence the resistance to sliding
movements of the level positioning member 15 can be reduced
efficiently.
As mentioned above, according to the first embodiment, since the
groove 17 is formed in the sliding surface 14a of the guide rail 14
for storing the grease 18 therein, the longevity of the lubricating
agent can be increased and therefore the resistance to sliding
movements of the level positioning member 15 can be reduced
efficiently. Accordingly, the embodiment offers the advantage of
being able to prevent wear in the sliding surface 14a of the guide
rail 14 and level positioning member 15 and therefore maintain the
accuracy of positioning the optical pickup 5.
Referring next to FIG. 6, there is illustrated a perspective view
showing a main part of a guide rail of an optical pickup carrying
system according to a second embodiment of the present invention.
Furthermore, FIG. 7 shows a cross-sectional view showing a main
part of a sliding portion of the optical pickup carrying system
according to the second embodiment.
In the figures, reference numeral 19 denotes a cavity formed in the
sliding surface 14a of the guide rail 19 for storing the grease 18
therein. A plurality of cavities 19 are arranged such that they are
running in two rows, and each of them is elliptical in horizontal
cross section. Each of the plural cavities 19 is aligned such that
the major axis thereof is directed in parallel with the direction
of moving the optical pickup 5.
Numerous variants may be made in the exemplary embodiment shown.
For example, each of the plural cavities 19 can be of rectangular
shape, of circular shape, or of any other shape in horizontal cross
section. Furthermore, one row of cavities 19 can be formed in the
sliding surface 14a, and three or more rows of cavities 19 can be
alternatively disposed in the sliding surface 14a. Since the other
structure of the pickup carrying system of this embodiment is the
same as that of the first embodiment, the description about the
other structure will be omitted hereinafter.
Next, a description will be made as to the operation of the optical
pickup carrying system of this embodiment. The basic operation of
the optical pickup carrying system of this embodiment is the same
as that of the first embodiment, and therefore the description
about the basic operation will be omitted hereinafter. In this
embodiment, since the grease 18 is stored in the plurality of
cavities 19 formed in the sliding surface 14a, scattering and a
spill of the grease 18 can be prevented as compared with the
above-mentioned prior art pickup carrying system. Therefore, the
longevity of the lubricating agent is increased.
Furthermore, since the two rows of cavities 19 arranged in the
guide rail 14 are running in parallel with the direction of moving
the optical pickup 5, an adequate amount of the grease 18 can be
applied to a part of the sliding surface 14a where a lot of
resistance to sliding movements of the level positioning member 15
is generated. Thus, the effect of lubricating can be enhanced and
hence the resistance to sliding movements of the level positioning
member 15 can be reduced efficiently.
As mentioned above, according to the second embodiment, since the
plurality of cavities 19 for storing the grease 18 therein are
formed in the sliding surface 14a of the guide rail 14, the
longevity of the lubricating agent can be increased and therefore
the resistance to sliding movements of the level positioning member
15 can be reduced efficiently. Accordingly, the embodiment offers
the advantage of being able to prevent wear in the sliding surface
14a of the guide rail 14 and level positioning member 15 and
therefore maintain the accuracy of positioning the optical pickup
5.
Referring next to FIG. 8, there is illustrated a perspective view
showing a main part of a guide rail of an optical pickup carrying
system according to a third embodiment of the present invention.
Furthermore, FIG. 9 shows a cross-sectional view showing a main
part of a sliding portion of the optical pickup carrying system
according to the third embodiment.
In the figures, reference numeral 20 denotes a groove formed in the
sliding surface 14b of the guide rail 14 for storing the grease 18.
The groove 20 is running in parallel with the direction of moving
the optical pickup 5. That is, the groove 20 is formed in the
sliding surface 14b similarly to the groove 17 formed in the
sliding surface 14a. Since the other structure of the pickup
carrying system of this embodiment is the same as that of the first
embodiment, the description about the other structure will be
omitted hereinafter.
Next, a description will be made as to the operation of the optical
pickup carrying system of this embodiment. The basic operation of
the optical pickup carrying system of this embodiment is the same
as that of the first embodiment, and therefore the description
about the basic operation will be omitted hereinafter. In this
embodiment, since the grease 18 is also stored in the groove 20
formed in the sliding surface 14b, scattering and a spill of the
grease 18 from the sliding surface 14b can be prevented as compared
with the above-mentioned prior art pickup carrying system.
Therefore, the longevity of the lubricating agent is increased.
Furthermore, since the groove 20 is formed in the guide rail 14 and
is running in parallel with the direction of moving the optical
pickup 5, an adequate amount of the grease 18 can be applied to a
part of the sliding surface 14b where a lot of resistance to
sliding movements of the plate spring 16 is generated. Thus, the
effect of lubricating can be enhanced and hence the resistance to
sliding movements of the plate spring 16 can be reduced
efficiently.
As mentioned above, according to the third embodiment, since the
groove 20 for storing the grease 18 therein is formed in the
sliding surface 14b of the guide rail 14, the longevity of the
lubricating agent can be increased and therefore the resistance to
sliding movements of the level positioning member 15 and spring
plate 16 can be reduced efficiently. Accordingly, the embodiment
offers the advantage of being able to prevent wear in the sliding
surface 14b of the guide rail 14 and spring plate 16 as well as
wear in the sliding surface 14a of the guide rail 14 and level
positioning member 15, and therefore position the optical pickup 5
with a higher degree of accuracy as compared with the first
embodiment.
Referring next to FIG. 10, there is illustrated a perspective view
showing a main part of a guide rail of an optical pickup carrying
system according to a fourth embodiment of the present invention.
Furthermore, FIG. 11 shows a cross-sectional view showing a main
part of a sliding portion of the optical pickup carrying system
according to the fourth embodiment.
In the figures, reference numeral 21 denotes a cavity for storing
the grease 18 in the sliding surface 14b of the guide rail 14. A
plurality of cavities 21 are arranged such that they are running in
two rows, and each od them is elliptical in horizontal cross
section. Each of the plural cavities 21 is aligned such that the
major axis thereof is directed in parallel with the direction of
moving the optical pickup 5. Since the other structure of the
pickup carrying system of this embodiment is the same as that of
the second embodiment, the description about the other structure
will be omitted hereinafter.
Next, a description will be made as to the operation of the optical
pickup carrying system of this embodiment. The basic operation of
the optical pickup carrying system of this embodiment is the same
as that of the second embodiment, and therefore the description
about the basic operation will be omitted hereinafter. In this
embodiment, since the grease 18 is also stored in the plurality of
cavities 21 formed in the sliding surface 14b, scattering and a
spill of the grease 18 from the sliding surface 14b can be
prevented as compared with the above-mentioned prior art pickup
carrying system. Therefore, the longevity of the lubricating agent
is increased.
Furthermore, since the two rows of cavities 21 are arranged in the
guide rail 14 and are running in parallel with the direction of
moving the optical pickup 5, an adequate amount of the grease 18
can be applied to a part of the sliding surface 14b where a lot of
resistance to sliding movements of the plate spring 16 is
generated. Thus, the effect of lubricating can be enhanced and
hence the resistance to sliding movements of the plate spring 16
can be reduced efficiently.
As mentioned above, according to the fourth embodiment, since the
plurality of cavities 21 for storing the grease 18 therein are
formed in the sliding surface 14b of the guide rail 14 in addition
to the plurality of cavities 19 in the sliding surface 14a, the
longevity of the lubricating agent can be increased and therefore
the resistance to sliding movements of the level positioning member
15 and spring plate 16 can be reduced efficiently. Accordingly, the
embodiment offers the advantage of being able to prevent wear in
the sliding surface 14b of the guide rail 14 and spring plate 16 as
well as wear in the sliding surface 14a of the guide rail 14 and
level positioning member 15, and therefore position the optical
pickup 5 with a higher degree of accuracy as compared with the
second embodiment.
Referring next to FIG. 12, there is illustrated a perspective view
showing a main part of a guide rail of an optical pickup carrying
system according to a fifth embodiment of the present invention.
Furthermore, FIG. 13 shows a cross-sectional view showing a main
part of a sliding portion of the optical pickup carrying system
according to the fifth embodiment.
In the figures, reference numerals 22a and 22b denote a pair of
projecting portions formed opposite to each other at both of
longitudinal sides of the sliding surface 14a of the guide rail 14,
respectively, for preventing the grease 18 from flowing out of the
both sides of the sliding surface 14a. In FIG. 13, reference
numerals 23a and 23b denote a pair of notch portions formed in one
surface of the level positioning member 15 of the optical pickup 5,
which abuts on the sliding surface 14a of the guide rail 14, so
that the pair of projecting portions 22a and 22b of the guide rail
can be passed smoothly through the pair of notch portions 23a and
23b when the optical pickup moves. Since the other structure of the
pickup carrying system of this embodiment is the same as that of
the second embodiment, the description about the other structure
will be omitted hereinafter.
Next, a description will be made as to the operation of the optical
pickup carrying system of this embodiment. The basic operation of
the optical pickup carrying system of this embodiment is the same
as that of the first embodiment, and therefore the description
about the basic operation will be omitted hereinafter. In this
embodiment, since the pair of projecting portions 22a and 22b is
disposed such that they project from both of the longitudinal sides
of the sliding surface 14a of the guide rail 14, respectively, the
grease 18 can be prevented from flowing out from the both sides of
the sliding surface 14a. Thus, the longevity of the lubricating
agent can be increased as compared with the first embodiment
mentioned above. During the movement of the optical pickup 5, the
pair of projecting portions 22a and 22b of the guide rail can be
passed smoothly through the pair of notch portions 23a and 23b.
As mentioned above, according to the fifth embodiment, since the
pair of projecting portions 22a and 22b is formed at both of the
longitudinal sides of the sliding surface 14a of the guide rail 14,
the longevity of the lubricating agent can be increased as compared
with the first embodiment and therefore the resistance to sliding
movements of the level positioning member 15 against the sliding
surface 14a can be reduced efficiently. Accordingly, the embodiment
offers the advantage of being able to prevent wear in the sliding
surface 14a of the guide rail 14 and level positioning member 15
and therefore position the optical pickup 5 with a higher degree of
accuracy as compared with the first embodiment.
As previously explained, the present invention offers the following
advantages.
In accordance with a preferred embodiment of the present invention,
there is provided an optical pickup carrying system comprising a
base, an optical pickup, a level positioning member for supporting
the optical pickup in cooperation with a plate spring, a guide rail
disposed in the base and provided with upper and lower sliding
surfaces on which the level positioning member and plate spring can
slide when the optical pickup moves, respectively, for guiding and
supporting the optical pickup in cooperation with the level
positioning member, and a lubricating agent storing mechanism
formed in the guide rail for storing a lubricating agent to furnish
it to at least one of the two sliding surfaces. Therefore, the
embodiment offers the advantage of being able to prevent wear in
the sliding surface of the guide rail and level positioning member
and therefore maintain the accuracy of positioning the optical
pickup.
In accordance with another preferred embodiment of the present
invention, the lubricating agent storing mechanism includes at
least one groove formed in the upper sliding surface which is
contact with the level positioning member and running in parallel
with a direction of moving the optical pickup. Therefore, the
embodiment offers the advantage of being able to supply an adequate
of the lubricating agent into a gap between the upper surface of
the guide rail and the level positioning member where a lot of
resistance to sliding movements of the level positioning member is
generated and hence reduce the resistance effectively.
In accordance with another preferred embodiment of the present
invention, the lubricating agent storing mechanism includes at
least one groove formed in the upper sliding surface which is
contact with the level positioning member and running in parallel
with the direction of moving the optical pickup, and at least one
groove formed in the lower sliding surface which is contact with
the plate spring and running in parallel with the direction of
moving the optical pickup. Therefore, the embodiment offers the
advantage of being able to supply an adequate amount of the
lubricating agent into a gap between the upper surface of the guide
rail and the level positioning member where a lot of resistance to
sliding movements of the level positioning member is generated and
a gap between the lower surface of the guide rail and the plate
spring where a lot of resistance to sliding movements of the plate
spring is generated, and hence reduce the resistance more
effectively.
In accordance with another preferred embodiment of the present
invention, the lubricating agent storing mechanism includes at
least one row of plural cavities formed in the upper sliding
surface which is contact with the level positioning member and
running in parallel with a direction of moving the optical pickup.
Therefore, the embodiment offers the advantage of being able to
supply an adequate of the lubricating agent into a gap between the
upper surface of the guide rail and the level positioning member
where a lot of resistance to sliding movements of the level
positioning member is generated and hence reduce the resistance
effectively.
In accordance with another preferred embodiment of the present
invention, the lubricating agent storing mechanism includes at
least one row of plural cavities formed in the upper sliding
surface which is contact with the level positioning member and
running in parallel with the direction of moving the optical
pickup, and at least one row of plural cavities formed in the lower
sliding surface which is contact with the plate spring and running
in parallel with the direction of moving the optical pickup.
Therefore, the embodiment offers the advantage of being able to
supply an adequate amount of the lubricating agent into a gap
between the upper surface of the guide rail and the level
positioning member where a lot of resistance to sliding movements
of the level positioning member is generated and a gap between the
lower surface of the guide rail and the plate spring where a lot of
resistance to sliding movements of the plate spring is generated,
and hence reduce the resistance more effectively.
In accordance with another preferred embodiment of the present
invention, the guide rail includes a pair of projecting portions
projected from both of longitudinal sides of the upper sliding
surface, and the level positioning member includes a pair of notch
portions through which the pair of projecting portions can be
passed when the optical pickup moves. Therefore, the embodiment
offers the advantage of being able to prevent the lubricating agent
from flowing out of the both sides of the upper sliding surface of
the guide rail.
Many widely different embodiments of the present invention may be
constructed without departing from the spirit and scope of the
present invention. It should be understood that the present
invention is not limited to the specific embodiments described in
the specification, except as defined in the appended claims.
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